This invention relates to an improved wheel end assembly having several features which provide better sealed bearings, and facilitate assembly and servicing of the components at the wheel end assembly.
Wheel end assemblies for drive axles typically include a housing surrounding the drive axle, and a fixed spindle for supporting a wheel hub. Typically, a flange extends radially outwardly from an end of the axle and is secured to the brake spider or torque plate by bolts, pins, or similar structure. Bearings support the wheel hub on the fixed spindle. It is somewhat difficult to adequately seal these bearings, which are positioned outwardly of the fixed flange on the spindle journals.
The known designs also raise challenges with regard to the assembly and servicing of the various components. As an example, to remove the wheel hub, one must typically drain the axle lube and remove the axle shaft from within the housing. Also, dissembling the wheel hub often results in disturbing the bearing package.
The housing itself has some deficiencies with regard to the arrangement and assembly of the components. To date, the spindle has been welded to a fixed housing. A brake flange has been welded to the outer periphery of the housing, and a torque plate or brake spider then welded or otherwise connected to that brake flange.
It is the goal of this invention to provide a better sealed assembly, and simplify the assembly and facilitate the maintenance of the wheel end assembly as described above.
In a disclosed embodiment of this invention, a wheel end spindle rotates with the drive axle shaft. The spindle in turn is connected to transmit rotation to the wheel hub. The wheel end assembly includes a bearing cup which surrounds the spindle and transmits the vertical wheel loads to the housing, with bearings positioned between this bearing cup and the spindle. In one embodiment, the bearing cup integrally provides the outer races, while in another, separate races are inserted. The outer housing ensures the bearings can be sealed simply and reliably. This facilitates the likelihood of long life for the bearings.
The spindle is preferably splined to be driven by the drive axle. Gear teeth transmit drive from the spindle to the hub. This simplifies the attachment by eliminating several parts required in the prior art and by eliminating the axle shaft flange.
In these embodiments, the wheel hub can be removed without complete disassembly of the wheel end assembly. That is, the axle shaft need not be removed for removal of the wheel hub. This facilitates servicing of the wheel hub, and the brake rotor, which can be serviced without removal of the axle shaft or disturbing the bearing package.
In further features, a rear housing has a forwardly extending boss that provides a piloting surface for the torque plate or brake spider, along with the bearing cup. The brake flange is preferably formed integrally at a location adjacent to this boss. The boss thus facilitates the assembly of these components.
In further features, a sensor is provided for communicating rotation information to the ABS system. The sensor preferably extends through the bearing cup, and monitors rotation of the spindle through a tone wheel arrangement, generally as is known. However, the tone wheel is mounted to the spindle in a unique fashion. In particular, a nut and a washer sandwich the tone wheel, and the tone wheel includes a flange received in a groove in the spindle. Thus, the tone wheel will rotate with the spindle. Tabs from the tone wheel preferably cause the nut to rotate with the tone wheel, assuring that the arrangement will have improved reliability.
These and other features of the present invention can be best understood from the following specification and drawings, following which is a brief description.